Electrocardiographic machine attachment



Aug. 6, 1940. G. ASHER ELECTROGARDIOGRAPHIG MACHINE ATTACHMENT Filed May 17, 1957 INVENTOR. fi/w/mm fisher ATTORNEYS Patented Aug. 6, 1940 UNITED STATES PATENT OFFICE ELECTROCARDIOGRAPHIC MACHINE ATTACHMENT Application May 17, 1937, Serial No. 143,106

4 Claims.

aforesaid electrical manifestations in such- 10 apparatus.

' One exemplification of equipment with which this invention may be used is electrocardiographic machines of the type employed by the medical profession, and a continuous, uninterrupted rec- 15 rd of a patients heart action may be obtained when such a machine is made to embody the improvements contemplated.

One of the important aims of this invention is to provide in an electrocardiographic machine,

20 means for viewing an oscillographic record, which means employs an endless movable strip, having thereon a coating of phosphorescent material, such material being of a nature as to glow for a short length of time whereby, and because 25 of the length of the strip, the glow or phosphorescence at a particular zone on the strip is lost before that zone is again acted upon by the beam of the first mentioned machine.

A still further object of the present invention 30 is the provision of a compact, durable, and simple attachment for electrocardiographic machines, that will be easy to combine with such machines, and capable of operatively holding a movable phosphorescent lag-screen in place.

35 Other objects of the invention will appear during the course of the following specification, referring to the accompanying drawing, wherein:

Figure 1 is a side elevation of an electrocardiographic machine attachment made to embody 40 the present invention, and showing the same on an electrocardiographic machine.

Fig. 2 is a vertical, cross sectional view through the attachments shown in Fig. 1, taken on line II-lI of that figure, and,

45 Fig. 3 is a fragmentary, cross sectional view through the lag screen or endless transparent phosphorescent strip.

Heretofore electrocardiographic machines have been used to produce photographic records of the 50 heart action, which record was made upon a sensitized transparent plate or film, and used as a record piece to study after the film or plate was exposed to the action of the electrocardiographic machine light beam. Thus an interval of 5 time elapsed before an attending physician could know of the condition of the patients heart and the nature of its action. It has always been desirable, therefore, to be able to record the heart action and to make direct observations of the record so'that irregularities might be rectified 5 or steps taken to protect a patient in the event he was undergoing the effects of anaesthetic or an operation.

The use of a continuously traveling phosphorescent strip in connection with the light beam of an electrocardiographic machine and means for operatively carrying the said strip, therefore, has become highly desirable. One physical embodiment of the invention is illustrated in the accompanying drawing, wherein the numeral 6 l5 diagrammatically designates a conventional electrocardiographic machine, which has a window 8 formed in the wall thereof, through which passes the light beam ID.

The attachment itself is made to include a housing l2, mounted upon base I. This housing has a viewing aperture i6 that should be disposed at an angle so that the operator may see but a portion of the hereinafter mentioned strip. An opening I8 is provided in base l4 and across this opening is disposed a lens 20, for the purpose of concentrating light beam HI and focusing the same upon a continuous or endless strip 22. This strip 22 is in the nature of a transparent film, and one manner of making the said strip 22 luminescent or phosphorescent is to provide a coating of phosphorescent crystalline mineral 24 thereon. Zinc sulphide has been found satisfactory as a coating for strip 22 because its property is such as to maintain the glow for a short period of time and thereafter lose the glow or phosphorescence.

Strip 22 is disposed within housing l2 so that it is in a darkened compartment best suitable for a clear view of the glowing portion thereof. The strip 22 is supported by a resilient apron 26, which presents bearing surfaces that press outwardly upon the endless strip 22 and maintain it taut. Apron 26 is carried by a support 28, and this support in turn has mounted thereon a shield 30, which overlies that length of strip 22 closest to viewing aperture l6. Thus means is provided for obscuring from the view of the operator, all of the length of strip 22 except that over and immediately adjacent to opening i8.

As the strip moves in the direction of the arrows, shown in Fig. 2, beam ill will cause coating 24 on strip 22 to glow, and such glow will continue at least until a particular point acted upon has reached spring bearing 22. From this point on it is desirable that the glow or phosphorescence be lost, and the length of strip 22 should be such as to permit complete loss of the glow before a given point on strip 22 reaches window 58 the second time.

Any suitable means may be employed for driving strip 22 at the properspeed. Obviously, a very slow movement is desirable, and in the embodiment illustrated herewith, an ordinary well known spring motor 34 is within housing i2 and geared to a drive spool 36, which has teeth 38 in engagement with the continuous series of openings 40 formed along the marginal edges of strip 22. It is conceivable to one skilled in the art that an electric motor (not here shown) or any other motivating means for strip 22 may be employed. When a spring motor is used, the same may be wound through the medium of crank 62, which extends exteriorly of housing l2, and conventional manually operable structure for stopping and starting motor 34 should also have a member 44 which extends exteriorly of housing l2 and within convenient reach of the operator. Motor 34 is carried by framework 46 and an adjusting element 48 for governor 50 may be manipulated to obtain the desired speed.

Both crank 42 and member 44 extend through openings 52 and 54 respectively, provided in housing l2, and when it is desired to replace strip 22, these members 42 and 44 may be removed from the operative position and housing l2 lifted from base l4.

Figs. 1 and 2 are fragmentary and condensed views, but the relation of viewing aperture i6 and that stretch of strip 22 between opening I8 and bearing 32 is such as to allow an unobstructed view of that portion of the strip at all times.

To accomplish this, the upper part of housing [2 has been angled slightly so that the major axis of viewing aperture i6 is intersected by that stretch of strip 22 occupying the position between opening l8 and bearing 32.

Manifestly, strip 22 may be disposed wherever desired, so long as it may be acted upon by beam ID as it is moved through a clrcumscribing path, and since the spirit of the invention is such as to contemplate other physical embodiments than those illustrated, it is desired to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

supporting the strip in the operative position with a viewable stretch thereof intersecting the light beam; and phosphorescent material on the strip whereby the light beam will create a glowing path along said viewable stretch as the strip is moved.

2. An attachment for electrocardiographic machines, having a window through which passes a beam of light, comprising a housing provided with a viewing aperture, and an opening in register with the window of the said machine; an endless strip of transparent material mounted within the housing for movement in a path of travel extending across the opening; a coating of phosphorescent material on said strip; a motor within the housing to move the strip; and a shield to obscure from view a part of said strip.

3. An attachment for electrocardiographic machines, having a window through which passes a beam of light, comprising a housing provided with a viewing aperture, and an opening in register with the window of the said machine; an endless strip of transparent material mounted within the housing for movement in a path of travel extending across the opening; phosphorescent material on said strip; a motor to move the strip; and guides to hold the strip in taut condition, said viewing aperture being positioned to permit the operator seeing but a certain stretch of said strip across and immediately adjacent to said opening in the housing.

4. The combination with an electrocardiographic machine having a window formed therein and adapted to project a light beam through said window, of an attachmentof the character described, comprising a 'closed housing provided with a viewing aperture through one wall thereof and an opening in the opposite wall through which passes said light beam from the electrocardiographic machine when said window and the opening are in register; a irame within the housing for supporting an endless strip of film; an endless strip of film having a coating or luminescent material on one side thereof; a motor for moving the said strip over said frame; means for varying the speed of the motor; and a shield concealing a portion of said strip.of film from view through the viewing aperture, another portion of said strip being in the line of vision through the viewing aperture and extending across the said opening in the said opposite wall of the housing, the length of said strip of film being suificient to permit complete loss of the glow thereon caused by the said light beam before a given point on the strip passes said window a second time.

GRAHAM ASHER.

a coating of 

